At present, the chamber end wall and the inner and outer side walls are made out of materials that are similar, having coefficients of expansion that are close, and the connection between the chamber end wall and said inner and outer side walls is implemented by rigidly bolting fittings which can be short in the axial direction.
In order to increase the efficiency of turbomachines, in particular in aviation, the temperature of the gases in the hot combustion zones are being raised ever higher, and the side walls are being protected by films of cooling air.
In order to ensure that the chamber end wall, which is usually made out of a material similar to that used for making the inner and outer side walls, is not subjected to levels of deformation that are irreversible due to excessively high temperature, the chamber end wall can be made out of a material that is different from that used for the radially-inner and radially-outer side walls, said material being capable of withstanding high temperatures. Under such circumstances, the coefficient of expansion of the material constituting the chamber end wall is different from that constituting the inner and outer side walls, and the connection between the chamber end wall and said inner and outer side walls by rigid bolting, i.e. using short fittings, becomes inconceivable from the point of view of the mechanical strength of the parts involved.
The attachment fittings are subjected to increasing stresses with increasing radial expansion differences between the bolting zones and the anchor points where the fittings are anchored on the chamber end wall, and these stresses become particularly great when the distance across the fitting between the anchor point and the bolting zone is short.
In order to reduce these stresses for predetermined differences in radial expansion, it is possible to increase the distance across the fitting between the anchor point and the bolting zone by using flexible fittings that are arch-shaped and that turn radially around the nuts of the bolts. However such flexible fittings occupy a large amount of space in the enclosure situated upstream from the chamber end wall, where upstream is defined relative to the normal upstream to downstream or inlet to outlet flow direction of gas flowing through the combustion chamber.
Unfortunately, the space available in said enclosure is limited, because of the presence of injector systems.